Vitamin E deficiency in humans is a rare occurence; the vitamin is so widely distributed in the diet that the deficiency syndrome only occurs in unusual instances of malabsorption. Reported clinical instances of E deficiency include abetalipoproteinemia (ABL) and cholestatic liver disease (CLD). In ABL neuromuscular abnormalities dominate the clinical syndrome; it is only after 2 decades of observations that we have established that many of these symptoms are due to vitamin E deficiency. In CLD the neuromuscular abnormalities develop more rapidly, but in both CLD and ABL amelioration of symptoms following vitamin E administration has been documented by objective electromyographic studies. There is need to supplement the sparse case reports with a systematic evaluation of many patients with ABL or CLD and to establish the degree ofresponse of each patient to vitamin E. We plan to evaluate the tissue levels of tocopherol using a needle aspiration biopsy of adipose tissue by the method we have newly developed. The tocopherol content measured will be used to establish a dose response relationship to define the level of oral or parenteral E required. To further understand the intracellular metabolic role of tocopherol, human monocyte-derived macrophages (HMD macrophages) in tissue culture will be studied. These cells have been chosen for study as macrophages are found in vivo laden with lipid where peroxidation of lipid may occur. These phagocytic cells also secrete peroxides and reactive aldehydes, so they potentially have a high requirement for an antioxidant, such as tocopherol. HMD macrophages will be used to investigate tocopherol uptake, its intracellular distribution and storage locations, the mobilization of tocopherol from lipid droplets and tocopherol utilization. The sensitivity of our tocopherol assay is such that the tocopherol content of cells in culture, as well as subcellular organelles isolated from those cells, is feasible. The other methodologies (measurement of cellular protein and cholesterol content, isolation of lipoproteins and culture of HMD macrophages, etc.) are all well established techniques in our laboratory. The tissue culture studies will show: 1) whether tocopherol uptake by cells results form uptake of LDL via the LDL receptor; 2) whether tocopherol can be stored by macrophages and if so whether the tocopherol in lipid droplets is available during times of tocopherol depletion; and 3) whether alteration in the medium fatty acid and tocopherol contents results in an altered production of reactive aldehydes.